Acrylamides have been classified as a potential carcinogen and neurotoxin that has been recently discovered to exist in varying levels in processed foods, such as fried, baked and cooked foods that are made from grain and vegetable based products such as potatoes. It has been proposed that acrylamide is formed as a result of the Maillard reaction between amino acids and reducing sugars. Asparagine, a major amino acid found in cereals (grains) and potatoes is thought to be the significant player in acrylamide production.
The Mailard reaction is responsible for producing much of the color and flavor in processed foods, such as those produced during the typical heating, cooking, frying, baking or roasting steps that accompany the production of breads, cereals, potato snacks, pastries, etc.
Asparagine has an amide group attached to a chain of two carbon atoms. The degradation of the amino acids in the presence of dicarbonyl products from the Mailard reaction causes the amino acid to become decarboxylated and deaminated to create an aldehyde. When glucose and asparagines are reacted at elevated temperatures, particularly those above 100° C., more typically above 120° C. and usually above 185° C. significant levels of acrylamides may be produced.
A focus of the present invention relates to novel uses of cyclodextrins, to reduce acrylamide levels in food products and food intermediates.
Cyclodextrins comprise a doughnut shaped or cyclical structure composed of between six to eight alpha-D-glucose units having a hydrophilic exterior (hydrophilic OH groups on the exterior rim) and a hydrophobic interior (electron dense hydrogen and oxygen atoms). Cyclodextrins are generally water soluble, free flowing crystalline powders that are substantially if not completely odorless and white in color.
Cyclodextrins are produced by the action of cyclodextrin glucosyltransferase (CGTase, EC 2.4.1.19) on hydrolysed starch syrups at neutral pH (6.0-7.0) and moderate temperature (35-40° C.). Alternatively, cyclodextrins can be produced in planta by the expression of the gene encoding CGTase in the food plant of interest.
Heretofore, starches such as cyclodextrins have not been employed or known for their beneficial reduction of acrylamide levels. Cyclodextrins have been used principally for the encapsulation of insoluble compounds on a molecular basis in order to enhance stability, reduce volatility and alter solubility as well as to increase shelf life of certain products. Such prior uses of cyclodextrins have been limited to flavor carriers and protection of sensitive substances against thermal decomposition, oxidation and degradation. In addition, more recently, cyclodextrins have also been used to remove fatty acids and cholesterol from animal fats and to remove cholesterol and cholesterol esters from egg yolks.
One potential solution to the high cholesterol problem teaches the treatment of the foodstuffs themselves with cyclodextrins rather than the consumer. U.S. Pat. Nos. 5,498,437, 5,342,633 and 5,063,077 discuss various processes for the removal of cholesterol and cholesterol esters from egg yolks, meat, animal fats, etc. It is thought that by reducing the level of cholesterol in such foodstuffs that overall levels of cholesterol may be reduced in consumers. However, processing steps to such foodstuffs increases the cost of delivering such products to market.
Another similar but apparently unrelated reference, which deals with removal of cholesterol from foodstuffs, is U.S. Pat. No. 5,232,725. This reference discusses a process for reducing cholesterol and free fatty acids in an animal fat and the material obtained from that process through the use of cyclodextrins. U.S. Pat. No. 5,223,295 also discusses the use of cyclodextrin to remove steroid based compounds from foodstuffs, particularly egg yolks. However, these patents suffer from the same drawbacks as those referenced above, in that the processing steps required to achieve the result adds another layer to delivering product to the market, causing delay and adding cost.
PCT Publications WO 99/59421 and WO 99/63841 disclose the use of phytosterols as a pharmaceutical agent or as an addition to certain foodstuffs for lowering cholesterol. The publication discusses that greater effectiveness of the phytosterols can be achieved when using a specified delivery vehicle such as a complexation with cyclodextrins. This represents little more than using cyclodextrins for a purpose that they are already known for, as a carrier for sensitive ingredients.
Another reference that teaches the use of beta-cyclodextrin as a carrier or delivery vehicle is U.S. Pat. No. 4,978,532. In this reference, dehydroepiandrosterone (DHEA) is delivered to the patient via a treatment patch. Beta-cyclodextrin is selected from a group of “permeation enhancers” to facilitate the delivery of the DHEA dose to the patient.
U.S. Pat. No. 5,624,940 the use of various complexes which include cyclodextrins for reducing bone loss and serum cholesterol levels in mammals. In this reference, the cyclodextrin, specifically hydroxypropyl-beta-cyclodextrin is used as a pharmaceutical delivery agent and not as an active ingredient useful in the reduction of serum cholesterol levels.
U.S. Pat. No. 4,877,778 discusses the administration of doses of 2-hydroxypropyl-beta-cyclodextrin at levels of up to 0.5 gm/kg per day. The cyclodextrin is used as a carrier to remove excess lipophiles from the system, specifically as set forth in the example, reduction of high vitamin A levels. With respect to serum cholesterol levels, the '778 patent suggests that the reduction of serum cholesterol levels achieved in the example is due to the system recognizing an overabundance of cholesterol and the serum cholesterol being subsequently “down-regulated. Such down-regulation is a known biologic phenomenon.” The '778 patent goes on to indicate that it is “the natural cholesterol carrying system which predominates and it is the new homeostasis which must be responsible for the observed drop in serum cholesterol.” Hence, the '778 patent does not suggest that the cyclodextrin is usable as a mechanism to bind bile acids or lipids to decrease reabsorption in the lower intestines and is merely cumulative of the prior art which illustrates the use of cyclodextrin as a particular pharmaceutical carrier to treat certain disorders.
Publications, patents and patent applications are referred to throughout this disclosure. All references cited herein are hereby incorporated by reference.
All percentages and ratios are calculated by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise stated.